Heterogeneous networks are one of many features in LTE Advanced (LTE-A). The idea is that a network should not only consist of a single type of eNodeB (eNB) like the case of a homogeneous network, but also deploy eNBs of different capabilities, e.g., of different transmit-power classes. These eNBs are referred to as macro eNBs (MeNB), pico eNBs (PeNB) and femto/home eNBs (HeNB), which are meant for basic outdoor, outdoor hotspot, and indoor/enterprise coverage, respectively. In other words, the HetNet deployment consists of deploying both high-power and low-power nodes with the low-power nodes placed throughout the layout of high-power nodes. Although HetNet offers opportunities to enable large-scale, low-cost deployment of small base stations below rooftops to improve user experience at hotspots or to improve the network coverage, it introduces new challenges to inter-cell interference coordination within the same channel as well as load balancing and user mobility in idle and active mode.